Semiconductor devices on which electronic parts such as semiconductor elements are mounted are required to endure heat cycles due to repeated operations, maintain electric connections and insulations, and stably support parts. Particularly, it is important for high-power semiconductor devices including semiconductor modules containing power semiconductor elements such as IGBTs (insulated gate bipolar transistors) to have high heat discharge properties and endure repeated heat cycles. If cracks occur in the solder at the junction of the power semiconductor element as a result of repeated heat cycles, the thermal resistance or electric resistance is increased and, in worse cases, the damage is accelerated by heat generation and the device fails to function.
Unexamined Japanese Patent Application KOKAI Publication No. 2006-237429 discloses a semiconductor device having electrode members and semiconductor elements mounted using the electrode members. The electrode members are composed of an insulating support plate (feeding plate) having multiple through-holes and multiple conductor posts (feeding posts) provided in the through-holes. The conductor posts are connected to the electrodes of the semiconductor elements. According to the technique of the Unexamined Japanese Patent Application KOKAI Publication No. 2006-237429, a semiconductor element is joined using the above-described electrode member comprising multiple conductor posts for one electrode. Then, thermal stress applied to the interface between the metal posts and semiconductor element is reduced compared with one conductor post being used for one electrode. Hence, the connection reliability of a semiconductor element is increased even if the metal posts and semiconductor element have significantly different thermal expansion abilities.
Unexamined Japanese Patent Application KOKAI Publication No. 2009-64908 discloses a semiconductor device having a support plate (feeding plate) consisting of, for example, a glass epoxy resin substrate and columnar conductors (conductor posts). The technique of the Unexamined Japanese Patent Application KOKAI Publication No. 2009-64908 improves electric conduction reliability and heat cycle endurance relating to heat conductivity.
The entire disclosure of Unexamined Japanese Patent Application KOKAI Publication No. 2006-237429 and Unexamined Japanese Patent Application KOKAI Publication No. 2009-64908 is incorporated herein.